s390/bp: remove __bpon()

There is no point in changing branch prediction state of a cpu shortly
before it enters stop state. Therefore remove __bpon().

Acked-by: Alexander Gordeev <agordeev@linux.ibm.com>
Reviewed-by: Sven Schnelle <svens@linux.ibm.com>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>

4 files changed, 6 insertions, 16 deletions

diff --git a/arch/s390/include/asm/processor.h b/arch/s390/include/asm/processor.h
index dd95fddd5dda..80ac0c1034dc 100644
--- a/arch/s390/include/asm/processor.h
+++ b/arch/s390/include/asm/processor.h
@@ -99,7 +99,6 @@ void cpu_detect_mhz_feature(void);
 
 extern const struct seq_operations cpuinfo_op;
 extern void execve_tail(void);
-extern void __bpon(void);
 unsigned long vdso_size(void);
 
 /*
diff --git a/arch/s390/kernel/entry.S b/arch/s390/kernel/entry.S
index d8890a6f5dee..58b85aedca22 100644
--- a/arch/s390/kernel/entry.S
+++ b/arch/s390/kernel/entry.S
@@ -159,21 +159,15 @@ _LPP_OFFSET	= __LC_LPP
 	.section .kprobes.text, "ax"
 .Ldummy:
 	/*
-	 * This nop exists only in order to avoid that __bpon starts at
-	 * the beginning of the kprobes text section. In that case we would
-	 * have several symbols at the same address. E.g. objdump would take
-	 * an arbitrary symbol name when disassembling this code.
-	 * With the added nop in between the __bpon symbol is unique
-	 * again.
+	 * The following nop exists only in order to avoid that the next
+	 * symbol starts at the beginning of the kprobes text section.
+	 * In that case there would be several symbols at the same address.
+	 * E.g. objdump would take an arbitrary symbol when disassembling
+	 * the code.
+	 * With the added nop in between this cannot happen.
 	 */
 	nop	0
 
-ENTRY(__bpon)
-	.globl __bpon
-	BPON
-	BR_EX	%r14
-ENDPROC(__bpon)
-
 /*
  * Scheduler resume function, called by switch_to
  *  gpr2 = (task_struct *) prev
diff --git a/arch/s390/kernel/ipl.c b/arch/s390/kernel/ipl.c
index 5f0f5c86963a..0f91cd401eef 100644
--- a/arch/s390/kernel/ipl.c
+++ b/arch/s390/kernel/ipl.c
@@ -649,7 +649,6 @@ static struct kset *ipl_kset;
 
 static void __ipl_run(void *unused)
 {
-	__bpon();
 	diag308(DIAG308_LOAD_CLEAR, NULL);
 }
 
diff --git a/arch/s390/kernel/smp.c b/arch/s390/kernel/smp.c
index d4888453bbf8..0126c5f6b904 100644
--- a/arch/s390/kernel/smp.c
+++ b/arch/s390/kernel/smp.c
@@ -348,7 +348,6 @@ static void pcpu_delegate(struct pcpu *pcpu,
 		abs_lc->restart_source = source_cpu;
 		put_abs_lowcore(abs_lc);
 	}
-	__bpon();
 	asm volatile(
 		"0:	sigp	0,%0,%2	# sigp restart to target cpu\n"
 		"	brc	2,0b	# busy, try again\n"
@@ -986,7 +985,6 @@ void __cpu_die(unsigned int cpu)
 void __noreturn cpu_die(void)
 {
 	idle_task_exit();
-	__bpon();
 	pcpu_sigp_retry(pcpu_devices + smp_processor_id(), SIGP_STOP, 0);
 	for (;;) ;
 }